As medical technology has developed to provide treatments for a greater number of medical conditions, and as hospitals have become automated to cope with chronic personnel shortages, the volume of information that is maintained for each patient has grown rapidly. As a result of this increase in information, it is often difficult for caregivers such as physicians and nurses to quickly find critical data about a patient.
To more fully understand the problem, consider the types of data which may be maintained for an individual patient. The hospital may want to know the name, address and insurance carrier for the patient as well as any special dietary, environmental or physical space requirements. The attending physician may want to know the patient's condition, medical history and recent vital sign data. If the patient has had any diagnostic tests such as X-rays or ultrasound images made at this hospital or at any other hospital, the attending physician may want to compare these test results with the results of newer tests to see how the patient's condition has progressed. In addition, if any medication has been prescribed, the physician may want to know the identity of the medication, when the last dose was taken and how the patient has complied with the dosage schedule.
The nursing staff covering the patient's room may want to have some indication of the patient's condition at the nurse station when the patient presses the nurse call station. For example, if the patient has been admitted for a heart condition, it would be helpful if any recent vital signs that may indicate the onset of a heart attack could be displayed at the nurse's station when patient presses the call button.
This type of information may be especially helpful when, due to a shortage of nurses or to an emergency situation, routine calls must be delayed. This information may also be helpful to a temporary nurse who is not familiar with the patients or with the hospital procedure.
Patient billing presents another data-keeping problem for hospitals. Charges for the physician, diagnostic laboratory and pharmacy may be separate from the hospital charges. In addition, many hospitals are allowing patients to charge non-essential items such as magazines and books to their hospital accounts. Currently, due to the time required to process these items through the hospital billing system and the insurance carrier, the charges that must be paid by the patient may not be known until several months after the hospital stay. Furthermore, some insurance carriers, such as Medicare, pay the physician based on the actual time spent with the patient. Using the present data gathering methods, billing data of this type may be difficult to obtain and to verify.
Recently, memory cards and smart cards have been used to hold a patients billing information and medical records. Three different types of cards, each about the size and thickness of an ordinary credit card, have been used for these purposes. One type of card has a non-volatile memory such as a magnetic stripe or a medium on which information may be recorded using a laser. These cards may hold a relatively large amount of information but this information can only be read by a relatively large and complex card reader. Another type of card includes a non-volatile memory such as an electrically alterable read only memory (EAROM) with external contacts on the surface of the card. Data stored in a memory of this type may be read using circuitry that is relatively inexpensive and compact. The third type of card combines a microprocessor with the non-volatile memory. In this configuration, the card may include programming to implement a security system which is designed to prevent unauthorized access to data on the card.
An exemplary system in which hospital billing information is kept on a memory card is described in an paper by A. Matsunobu et al. entitled "Kapiolanai Women's And Children's Medical Center" Computing Healthcare Vol 7, No. 6 PP 20-26, 1986. A system for keeping patient records on a laser card system is described in a paper by J.H.U. Brown et al. entitled "A New Patient Record System Using The Laser Card" Optical Information Systems, Vol 8, No. 4, PP 156-161 July-August 1988. Two systems which use a memory card to hold patient records are described in a paper by R.C. Livermore entitled, "Health Service Applications In England And Wales" Smart Card 88, PP 5-10, June 1988.
All of these systems merely record the information on the card so that it may be read by a caregiver at a later time. These systems fill a need by allowing the caregiver to obtain the medical records directly from the patient rather than having to request the data from the various hospitals, physicians and pharmacists which have served the patient. None of these systems provide for any automatic interaction with information stored on the card.
Another problem faced by care givers and by hospital administrators is determining the location of key personnel and equipment. In an emergency it may be of critical importance to be able to quickly locate the attending physician and to communicate the nature of-the emergency situation. Moreover, when special equipment is required to treat an emergency condition, it is desirable that this equipment be quickly located with a determination as to its availability.
Current systems for locating personnel within a hospital rely on audio paging systems, sign-in and sign-out sheets and broadcast paging systems. In a given situation, the audio paging system would be tried first. This system may not be effective if the person to be located is in an area where the paging system is not functioning properly or has been turned down, or if the person has left the hospital. After an unsuccessful audio page, the sign-in and sign-out sheets may be checked. If, however, the person to be located forgot to use the sign-out sheet, critical time may be lost in a second attempt to use the audio paging system. In addition, a search of the sign-in and sign-out sheets may require more time than is available in an emergency situation.
When the person to be located is outside of the hospital, broadcast paging systems are often the best way to convey an important message. These systems require the individual trying to locate the person to call a paging service, leave a message, wait for the paging service to send the message to the individual's pocket pager and then wait for the person being paged to call the paging service, receive the message and respond. This system is too time consuming and unwieldy for use inside the hospital environment.
Physicians who have a private practice and who are associated with a hospital may have difficulty receiving emergency calls while they are in the hospital but not in their hospital office. Calls of this type may be handled either through the audio paging system of the hospital or through a broadcast paging system. Neither of these solutions is particularly desirable, since, the physician may not hear or understand the message sent through the audio paging system and may not wish to be interrupted by a pocket beeper while attending to a patient in the hospital.
Another problem with audio paging systems used in a hospital environment is noise pollution. These systems are often louder than necessary and may add an element of stress to an environment where stress is desirably kept to a minimum.
In addition to locating caregivers, it may also be desirable to quickly locate patients who are not in their rooms. This is particularly true for patients that have recently been moved, say from an intensive care unit to a room, or for patients who tend to wander or who have memory problems. Patients such as these may not realize they are being paged through an audio paging system or, if they do, may be unable to respond. In these instances, hospital personnel must be available to search for the patients or the patients must be restrained to prevent them from wandering.
Exemplary existing locator systems use either radio frequency signals or infra-red signals to communicate the position of a mobile individual or object to a network of receivers. One such system, the Infra-Com.TM. Locating And Signaling System available from United Identification Systems Corp. is designed for use in a hospital environment. Using this system, a network of infra-red transceivers located throughout a hospital can both transmit data to and receive data from a battery-operated badge worn by hospital personnel or attached to the equipment to be located. This badge transmits a programmed identification signal to the network allowing the position of the badge to be indicated on a floor plan of the hospital.
Another exemplary system, the TELOC PLS Personnel Locator System available from TELOC INC., also uses two-way infra-red signalling to communicate the position of a battery powered badge in a distributed sensor network. In addition, the TELOC system may be coupled to a private branch exchange (PBX) to allow telephone calls for an individual to be routed to the telephone that is closest to the badge or to direct an intercom message to that telephone, thus providing an alternative to an audio paging system.
Each of these systems is limited in the data that may be conveyed between the stationary transceiver network and the transceiver on the badge. In the described systems, only identification information and an indication that switches on the badge have been activated may be transmitted from the badge.
Furthermore, if the transceiver on the badge fails or is damaged, a blank badge must be programmed to take its place. This programming operation may be time consuming, leaving the individual or the piece of equipment invisible to the locating system for that period of time.
Yet another problem faced by hospitals is in preventing unauthorized access to restricted areas, such as drug lockers and hospital pharmacies. Currently, these areas require special security measures, such as guard personnel or complex electronic apparatus to verify the identity of an authorized individual. These security measures are an annoyance to those who are subject to them and may increase the response time to an emergency situation when a critical medication is only available in the drug locker.
Although the discussion so far has focused on the hospital environment, other institutions have similar problems. For example, in correctional institutions, it may be necessary to quickly locate guards or trustees to either respond to a disturbance or to ensure that there is sufficient surveillance of the prison grounds. In an emergency, where, for example, a guard is being attacked by an inmate, it may be desirable for the guard to be able to quickly alert a central facility so that reenforcements may be sent. To provide this type of warning, the guards at many correctional facilities rely on walkie-talkies. When the situation develops quickly, however, there may not be time for the guard to use the walkie-talkie and to protect himself against the attacker.
Many industrial security systems augment electronic intruder detectors with hired guards who follow a fixed route through the facility. To ensure that these guards walk the designated route at the appointed times, the guards may be required to carry a clock mechanism into which keys, found at key-stations along the way, may be inserted. These keys are designed to be inserted only in a prescribed order. The clock mechanism records the time at which the keys were inserted to provide a record of when the guard passed the key station. Systems of this type are subject to abuse if, for example, short-cuts exist between successive key stations. Moreover, the clock mechanisms tend to be bulky and may impede the guard in his investigation of an abnormal situation.
A night watchman at an industrial plant may have the same need as a prison guard to signal for help in an emergency situation, and, like a prison guard may not have time to use a walkie-talkie.
Another institution in which data keeping is important but often burdensome is in colleges and universities. In this environment it may be desirable to know what courses a student is taking, whether the student resides in on-campus housing and, if so, to know the student's address. The college administrators may also want to know if a particular student has an outstanding balance on his tuition bill. In addition, the student may want to be able to charge expenses to an account which is sent directly to his parents.
In many colleges and universities, the databases which keep track of this type of information are not integrated. Some information may only be available from a terminal coupled to a central computer while other information may only be recorded in a paper filing system.